U.S. Pat. Nos. 4,116,856; 4,116,858; 4,159,311; and 4,221,767 show the preparation of crystalline lithium aluminates by reacting of lithium compounds with hydrous alumina under certain conditions. The so-prepared aluminates are useful in selectively removing Li.sup.+ ions from aqueous solutions. The crystalline aluminates are identified, generally, by the empirical formula LiX.2Al(OH).sub.3 where X is a halogen of the group chlorine, bromine, or iodine, especially chlorine. It is realized, of course, that there are waters of hydration accompanying the aluminate crystals. It is also known that Al.sub.2 O.sub.3 is used as a packing material for gas chromatograph columns.
It has now been found that lithium aluminates such as are made in accordance with the above named patents and by other techniques discussed hereinafter, are useful in separating hydrocarbon fractions carried in a gas stream especially when the aluminates are not deposited within, or upon, a particulate substrate.